Silt terrace erosion permanent prevention

ABSTRACT

The present invention is directed to a new and useful labor saving method of constructing Λ-shaped dam structures to retain silt in farm field intermittent watercourses by utilizing 10″ and 2″ black plastic drainage tile.

B. REFERENCES

[0001] U.S. patent documents cited: U.S. Pat. No. 6,322,289 B1 November2002 Nolan

C. FEDERAL SPONSORED R&D

[0002] None

D. MICROFICHE APPENDIX

[0003] None

E. BACKGROUND OF THE INVENTION

[0004] Soil erosion in farm field gullies is a major problem forfarmers. Until recently, there was no low cost method of abating thedamage caused by the natural erosion of water coursing such fields.

[0005] The construction of Λ-shaped dam structures with dirt filled, nonbiodegradable plastic sacks as described in the process called STEP,U.S. Pat. No. 6,322,289, Nov. 27, 2001, is a solution to this problem.However, it is a labor intensive method. By substituting 10″ blackplastic drainage tile for the dirt filled sacks it saves time and laborand there is vastly increased strength and durability. The improvementwas not readily obvious at the inception of the concept of the patentfor silt terrace erosion prevention.

F. DESCRIPTION OF PRIOR ART

[0006] Black plastic drainage tile is commonly used to drain subsoilwater and it is buried in the ground throughout the field. It isdurable, reasonably inexpensive and generally available for suchplacement. However, no previous construction of a farm-field gully damstructure using drainage tile is known.

[0007] It is the object of the present invention to provide an alternatemethod of constructing silt terrace erosion permanent prevention damswhich are more durable and less time and labor consuming to put inplace, and which retain the silt trapping features of the STEP process.

G. SUMMARY OF THE INVENTION

[0008] The object of the invention is accomplished by placing a Λ-shaped10″ black plastic drainage tile, secured by anchors in the gully. Thelength of each leg of the Λ-shape is determined by the distance from theApex to each side bank. The Λ-shape is obtained with the use of a 90degree angle coupler. A 2″ plastic drain tile is placed beneath andalong the downstream exterior of the 10″ Λ tile to baffle erosion byfalling water. Each open end of the Λ leg is closed with an end cap andstabilized with a dirt filled sack.

[0009] As with the dirt filled sack STEP structures, water flowing overthe 10″ tile is drawn to the center and away from the side banks. Waterheld upstream in the temporary pool, deposits silt. The water is slowlyevacuated from the temporary pool down through the 2″ drain tile,thereby reducing scouring of the stream bed below.

H. BRIEF DESCRIPTION OF DRAWING

[0010]FIG. 1 represents an overhead view of the silt terrace erosionpermanent prevention tile dam structure.

I. DETAILED DESCRIPTION

[0011] A cavity is dug along the thread of the stream bed for a 2″drainage tile (1). Excavated dirt is used to fill woven plastic sacks(7).

[0012] Upstream ends of two 10″ diameter drainage tiles (Λ legs) (3) arefixed into a 90 degree angle (4) and the Λ thus formed is placed in theditch with the Λ pointing upstream. The length of the Λ legs aredetermined by the width of the gully at the site. End caps (5) are fixedat each downstream end of the 10″ Λ. Dirt filled sacks are placed overthe ends and packed against the side banks of the gully to prevent sidebank erosion.

[0013] At the exterior base of the 10″ tile Λ a length of 2″ drainagetile is placed to baffle erosion by falling water (2).

[0014] The entire dam structure is secured with “J” shaped re'rods (6).One “J” re'rod is driven into the stream bed to anchor both the 90degree angle and the 2″ baffle tile at the apex of the Λ. Another “J”shaped re'rod is driven at the downstream inside end of each Λ leg topin the ends of the Λ and the dirt filled sacks.

[0015] Water flowing downstream (8) will pool above this dam structureand will occasionally flow over the 10″ drainage tile dam to the threadof the stream bed below. Water which pools above the dam (9) will beslowly evacuated through the 2″ drainage tile and will deposit silt andbuild up the silt terrace to the adjacent farm field level andeventually restore the grass strip and promote contour farming.

As my invention, I claim:
 1. A silt terrace erosion permanent preventiondam structure utilizing 10″ diameter and 2″ diameter black plasticdrainage tiles in lieu of dirt filled woven plastic fabric sacks.